This invention relates to cleaning solutions. In one aspect, the invention relates to cleaning solutions for removing uncured polyester resin systems from surfaces of processing equipment while in another aspect, this invention relates to cleaning solutions comprising one or more dibasic acid esters, at least one free radical polymerization inhibitor, and at least one chelating agent. In yet another aspect, this invention relates to the use of these cleaning solutions as a cleansing flush for polyester resin processing equipment.
U.S. Pat. No. 5,064,557 to Fusiak teaches a resin cleaner composition for use as a cleaning solvent to remove cured, partially cured and uncured polyester or vinyl ester resins containing a free radical polymerization C initiator from fiberglass fabrication tools. These compositions are characterized by the presence of a free radical inhibitor which suppresses the rate of free radical polymerization, and thus allows the resin to be loaded in increased amounts into the composition without an accompanying increase in the polymerization in the resin, i.e. without the resin gelling. These compositions of Fusiak contain a free radical inhibitor, e.g. hydroquinone, a solvent (e.g. N-methylpyrrolidone), and optionally a diluent, such as a dibasic acid ester (DBE). While these compositions are generally effective for their intended purpose, the amount of resin that can be loaded into the composition is not completely satisfactory.